Improvement in scroll-saws



Hr HUM PHREYKL HE'NRY BICKFORIL- Improvement in Scroll-Saws.

Patented May 23,1871.

. UUNITEDJSTATES PATENT OFFIGE HUGH H. HIlMPHRE'Y AND HE RY BICKFORD, on CINCINNATI, OHIO,

AssIe ons TO HENRY BIOKFORD.

IMPROVEMENT IN SRQLL-SAWS.

We, HUGH H. HUMPHREY and HENRY BICKFORD, both of Cincinnati, Hamilton county, State of Ohio, have invented a certain new and useful Improvement in Scroll- ?aws, of which the following is a specifica- N atnre and Objects of Invention. Our invention consists, first, in a peculiar combination of frame, saw, and rolling arms,

Description of the Accompanying Drawing.

Figure 1 is a perspective view of a scrollsaw embodying our invention. Fig. 2 isa section through the arms of the saw in a direction from front to rear of the machine.

Fig. 3 is a section through the arms of the saw in a direction at right angles to Fig. 2, and through the line X X. I

General Description.

The frame A is composed of a column, a, table b, and post 0. The post a, for some classes of 'work, may be built up from the table b in the manner shown, or the post 0 may be suspended from the floor above, leaving an open space between the table and the bottom end of the post, as is common in the construction of scroll-saws, to give perfect. unlimited freedom to the movement of the material. The frame A is fitted with blocks B; B, which constitute a part of the frame, and on which the arms of the saw roll. Their front faces are in the same plane, and the upper one may be adjustable vertically to admit of the introduction of different lengths of saws. O is the saw. It is connected -to the frame Aloy the vibrating rolling arms D D, which are made, preferably, of light I stamped plates, connected closely together where they join the saw, and separate sufficie'ntly where they press against the blocks, to give a broad base, as shown. The arms are connected to the saw by pins 0 c, the connection at the top admitting of the saw being detached to pass through holes in the work. The upperarm D is secured to the block .in the same manner as the lower oneD. v

The connection is made as follows: A link, E, is hinged to the block B at e, and to the arm D at e.- A bent spring, F, serves the double purpose of pressing the link so as to force the arm D against the face of the block B, and also to give the upward stroke to the saw. The latter of thetwo, however, is not necessary where the saw is operated by a stiff connecting-rod, it being only necessary then to use a spring of a character adapted only to keep the arms against the face of the block.

It will be seen that, owing to the width.

.of the link E and the character of its connection to the block and arm, the arm cannot twist or move laterally, and is confined to a vibratory rolling motion, which gives the necessary rectilinear reciprocating motion to the saw, accompanied by very slight friction. I

Gr is the driving-shaft, properly journaled in the frame. Its plate H is'fitted witha crankwrist, I, for driving the saw. 7

In order to provide a'connection between the saw and its driving-crank wrist which will have but little power to cause vibration of the machine under high speed, we use a catgut pitman, J, or equivalent flexible material. As this pitman, when in connection with a machine having a spring to carry the saw through the upward stroke, is used to pull the saw through the downward stroke only, the flexibility of it is no objection.

Claims.

1. The combination of the ways B B, saw 0, rolling arms D D, links E E, and suitable springs F to confine the arms to the prescribed path on the ways, substantially as and In testimony of which invention we hereunto set our hands.

HUGH H. HUMPHREY. H. BIGKFORD.

for the purpose set forth.

2. In combination with the frame A, saw 0, arms D D, and links E, the springs F, adapted not only to press the arms against Witnesses: the frame, but to give the upward stroke to FRANK MILLWARD,

the saw. J. L. WARTMANN. 

